%0 Journal Article
%T Towards Direct Simulation of Future Tropical Cyclone Statistics in a High-Resolution Global Atmospheric Model
%A Michael F. Wehner
%A G. Bala
%A Phillip Duffy
%A Arthur A. Mirin
%A Raquel Romano
%J Advances in Meteorology
%D 2010
%I Hindawi Publishing Corporation
%R 10.1155/2010/915303
%X We present a set of high-resolution global atmospheric general circulation model (AGCM) simulations focusing on the model's ability to represent tropical storms and their statistics. We find that the model produces storms of hurricane strength with realistic dynamical features. We also find that tropical storm statistics are reasonable, both globally and in the north Atlantic, when compared to recent observations. The sensitivity of simulated tropical storm statistics to increases in sea surface temperature (SST) is also investigated, revealing that a credible late 21st century SST increase produced increases in simulated tropical storm numbers and intensities in all ocean basins. While this paper supports previous high-resolution model and theoretical findings that the frequency of very intense storms will increase in a warmer climate, it differs notably from previous medium and high-resolution model studies that show a global reduction in total tropical storm frequency. However, we are quick to point out that this particular model finding remains speculative due to a lack of radiative forcing changes in our time-slice experiments as well as a focus on the Northern hemisphere tropical storm seasons. 1. Introduction Hurricanes and tropical cyclones are arguably the most devastating meteorological events in both loss of human life as well as financial costs. Following the most active Atlantic hurricane season ever recorded in 2005, the debate as to the influence a warmer climate might have on the statistics of tropical cyclones has become more urgent. If the frequency or intensity of such storms were to change, the impacts could be severe. The number of tropical cyclones has been remarkably stable since 1970 averaging about ninety storms globally per year [1, 2]. No statistically significant trend in this number of tropical cyclones has been observed in the period 1970 to present [1]. However, there is evidence of significant trends in tropical cyclone intensity and duration over this period. Holland and Webster [3] found that the number of Atlantic tropical cyclones has increased in a statistically significant sense and Emanuel [4] has correlated increases in a hurricane power index with increases in North Atlantic sea surface temperatures. Elsner et al. [5] have found a twenty-six year positive trend in the maximum wind speeds of Atlantic storms in the 70th percentile and greater by an analysis of satellite records. A causal connection between warming in the main cyclogenesis regions and human activities has been established to a high degree of
%U http://www.hindawi.com/journals/amete/2010/915303/